Apparatus and method for transmitting a MAC PDU based on MAC header type information

ABSTRACT

An Apparatus and methods for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU) is disclosed. The method comprises steps of receiving, by a mobile station (MS) from a base station (BS), a dynamic service addition request (AAI_DSA-REQ) message requesting to create a service flow, wherein the AAI_DSA-REQ message comprises a first MAC header type parameter indicating a type of a MAC header included in the MAC PDU of the service flow and a flow identifier (FID) identifying a connection associated with the service flow; transmitting, by the MS to the BS, a dynamic service addition response (AAI_DSA-RSP) message in response to the AAI_DSA-REQ message, wherein the AAI_DSA-RSP message comprises a second MAC header type parameter indicating the type of a MAC header included in the MAC PDU of the service flow; and communicating with the BS using the MAC PDU comprising the MAC header indicated by the second MAC header type parameter; wherein the MAC header type parameter indicates one of a generic MAC header (GMH) for general data packet transmission and a short-packet MAC header (SPMH) for small data packet transmission and a non-ARQ connection.

This application is the National Phase of PCT/KR2010/005961 filed onSep. 2, 2010, which claims priority under 35 U.S.C. 119(e) to U.S.Provisional Application Nos. 61/239,077 filed on Sep. 2, 2009 and61/255,475 filed on Oct. 27, 2009 and under 35 U.S.C. 119(a) to PatentApplication No. 10-2010-0033172 filed in Korea on Apr. 12, 2010, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

TECHNICAL FIELD

The present invention relates to a mobile communication system, and moreparticularly, to an apparatus for transmitting and receiving MAC PDU(medium access control protocol data unit) using MAC header typeinformation and method thereof.

BACKGROUND ART

Generally, an internet based communication system includes a protocolstack consisting of five layers. And, a configuration of each protocollayer is shown in FIG. 1.

FIG. 1 is a diagram for one example of an internet protocol stack usedin general.

Referring to FIG. 1, an internet protocol stack consists of anapplication layer (i.e., a most upper layer), a transport layer, anetwork layer, a link layer and a physical layer in order. Theapplication layer is the layer for supporting such a network applicationas FTP (File Transfer Protocol), HTTP (Hypertext Transfer Protocol, TCP(Transmission Control Protocol), UDP (User Datagram Protocol) and thelike. The transport layer is the layer responsible for an inter-hostdata transport function using TCP/UDP. The network layer is the layerfor setting a data transport path from a source to a destination via thetransport layer and IP protocol. The link layer is the layer responsiblefor data transmission between neighbor network entities and MAC (mediumaccess control) via PPP/Ethernet protocol and the like. And, thephysical layer is a lowest layer for performing a data transmission by abit unit using a wire/wireless medium.

FIG. 2 is a diagram for operation of each layer for data transmissionused in general.

Referring to FIG. 2, a transport layer of a transmitting side generatesa new data unit by adding header information H+ to a message payload Mreceived from an application layer that is an upper layer. The transportlayer transfers the new data unit to a network layer that is a lowerlayer. The network layer generates a new data unit by adding headerinformation Hn used by the network layer to the data received from thetransport layer and then transfers this data unit to a link layer thatis a lower layer.

Subsequently, the link layer generates a new data unit by adding headerinformation H1 used by the link layer to the data received from theupper layer and then transfers it to a physical layer that is a lowerlayer. The physical layer transfers the data unit received from the linklayer to a receiving side.

Meanwhile, a physical layer of the receiving side receives the data unitfrom the transmitting side and then transfers the received data unit toa link layer that is an upper layer of the physical layer. The receivingside processes a header added to each layer and then transfers theheader removed message payload to an upper layer. Through this process,data transceiving is performed between the transmitting side and thereceiving side.

For the data transceiving between the transmitting side and thereceiving side, as shown in FIG. 2, each layer adds a protocol headerand then performs such a control function as data addressing, routing,forwarding, data retransmission and the like.

FIG. 3 is a diagram of a protocol layer model defined in a wirelessmobile communication system based on IEEE 802.16 system used in general.

Referring to FIG. 3, a MAC layer belonging to a link layer can consistof three sublayers.

First of all, a service-specific convergence sublayer (service-specificCS) modifies external network data received via a convergence sublayerservice access point (CS SAP) into MAC SDUs (service data units) of aMAC sublayer (common part sublayer: CPS) or maps the corresponding data.This layer can include a function of sorting SDUs of external networkand then linking a corresponding MAC service flow identifier (SFID) witha connection identifier (CID).

Secondly, a MAC CPS is a layer of providing such a core function of theMAC as system access, bandwidth allocation, connection setting andmanagement and the like. The MAC CPS receives data sorted by a specificMAC connection from various convergence sublayers via the MAC SAP. Inthis case, a QoS (quality of service) is applicable to the datatransmission and scheduling via a physical layer.

Thirdly, a security sublayer is able to provide such a function asauthentication, security key exchange and encryption.

The MAC layer is a connection-oriented service and is implemented withthe concept of transport connection. When a mobile station registerswith a system, a service flow can be provided by a negotiation between amobile station and a system. If a service request is changed, a newconnection can be set. In this case, the transport connection definesmapping between peer convergence processes using MAC and service flow.And, the service flow defines QoS parameters of MAC PDU exchanged in thecorresponding connection.

The service flow on the transport connection plays a core role inmanaging and operating the MAC protocol and provides a mechanism foruplink and downlink QoS managements. In particular, service flows can becombined with a bandwidth allocation process.

In the general IEEE 802.16 system, a mobile station is able to have a48-bit universal MAC address for each radio interface. This addressuniquely defines a radio interface of a mobile station and is usable toset an access of the mobile station during an initial ranging process.Since a base station verifies mobile stations using differentidentifiers (ID) of the mobile stations, respectively, the universal MACaddress is usable as a portion of an authentication process.

Each connection can be identified by a 16-bit connection identifier(CID). While initialization of a mobile station is in progress, twomanagement connection pairs (i.e., uplink and downlink) are establishedbetween a mobile station and a base station. And, three pairs includingthe management connections are selectively usable.

In order for a transmitting end and a receiving end to exchange datawith each other in the above described layer structure, assume a case oftransmitting MAC SDUs (medium access control service data units). Inthis case, the MAC SDU is processed into MAC PDU (medium access controlpacket data unit). In order to generate such a MAC PDU, a base stationor a mobile station enables a MAC header to be included in thecorresponding MAC PDU.

DISCLOSURE OF INVENTION Technical Problem

Generally, in case of applying segmentation, packing or automaticretransmit request (ARQ) to a packet to transmit, it is able to use afragmentation & packing extended header among extended headers to enablerelevant information to be included in a corresponding MAC PDU.

In this case, data, which is generated in a fixed small size withpredetermined periodicity like a voice packet such as VoIP (voice overinternet protocol), is generally transmitted without having segmentationor packing. Moreover, in case of performing an error check, hybridautomatic retransmit request (HARQ) reordering applied to MAC PDU unitis used instead of ARQ reordering applied to MAC SDU unit. Therefore,when HARQ reordering is substantially performed on such a packet asVoIP, MAC PDU is accompanied by FPEH to include a sequence number for acorresponding data required for discriminating retransmitted data fromnew data transmitted next to the retransmitted data.

However, in this case, even if FPEH having a size of minimum 2 byte isadded to a VoIP packet, a size of a MAC header becomes equal to orgreater than 3 bytes to result in unnecessary resource waste in case ofVoIP packet transmission.

Solution to Problem

Accordingly, the present invention is directed to an apparatus fortransmitting and receiving MAC PDU (medium access control protocol dataunit) using MAC header type information and method thereof thatsubstantially obviate one or more of the problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide an efficient compactMAC header (i.e. a short-packet MAC header) structure including asequence number and a method of providing a service using the same.

Another object of the present invention is to provide a more efficientmethod of providing a service by sharing information on a type of a MACheader to use for MAC PDU, which is to be transmitted, in the course ofa service connection performed between a base station and a mobilestation for MAC PDU transmission.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims thereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a methodfor communicating in a wireless access system using a medium accesscontrol protocol data unit (MAC PDU), the method comprises steps ofreceiving, by a mobile station (MS) from a base station (BS), a dynamicservice addition request (AAI_DSA-REQ) message requesting to create aservice flow, wherein the AAI_DSA-REQ message comprises a first MACheader type parameter indicating a type of a MAC header included in theMAC PDU of the service flow and a flow identifier (FID) identifying aconnection associated with the service flow; transmitting, by the MS tothe BS, a dynamic service addition response (AAI_DSA-RSP) message inresponse to the AAI_DSA-REQ message, wherein the AAI_DSA-RSP messagecomprises a second MAC header type parameter indicating the type of aMAC header included in the MAC PDU of the service flow; andcommunicating with the BS using the MAC PDU comprising the MAC headerindicated by the second MAC header type parameter; wherein the MACheader type parameter indicates one of a generic MAC header (GMH) forgeneral data packet transmission and a short-packet MAC header (SPMH)for small data packet transmission and a non-ARQ connection.

Preferably, the AAI_DSA-REQ message further comprises service flowparameters specifying traffic characteristics and schedulingrequirements of the service flow and convergence sublayer parametersencodings specifying convergence sublayer specific parameters. In thiscase, the service flow parameters comprise a link indicator indicatingwhether parameters for the MAC PDU transmission is uplink or a downlink.In addition, the small data packet may be a voice over internet protocol(VoIP) data packet which has a predetermined fixed size with apredetermined periodicity.

Preferably, the SPMH consists of the flow identifier (FID) field, anextended header group presence indicator (EH) field, a length field anda sequence number (SN) field. The FID field identifies the connectionused for the transmission of the MAC PDU; the EH field indicates whetheran extended header group is present following the SPMH; the length fieldindicates a length in bytes of the MAC PDU including the SPMH and anextended header if present; and the SN field indicates a payloadsequence number of the MAC PDU and increments by one for each MAC PDU.The SN field is used for an HARQ (hybrid-automatic retransmissionrequest) scheme.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, the present invention disclosesstation for communicating in a wireless access system using a mediumaccess control protocol data unit (MAC PDU). The station comprises atransmitter; a receiver; and a processor configured to generate the MACPDU, wherein the MAC PDU comprises a MAC header indicated by a MACheader type parameter determined during a dynamic service flow creationprocedure, and wherein the MAC header type parameter indicates one of ageneric MAC header (GMH) and a short-packet MAC header (SPMH).

Preferably, the processor comprises a convergence sublayer, a servicedata unit (SDU) fragmentation or packing function unit, and a MAC PDUformation module which are used for generating the MAC PDU.

Preferably, the dynamic service flow creation procedure is performed byexchanging a dynamic service addition request (AAI_DSA-REQ) message anda dynamic service addition response (AAI_DSA-RSP) message.

According to the other embodiment of the present invention, the stationcommunicates with another station using the MAC PDU comprising the MACheader indicated by the second MAC header type parameter, and whereinthe MAC PDU is constructed by the MAC PDU generating unit.

Preferably, the AAI_DSA-REQ message comprises service flow parametersspecifying traffic characteristics and scheduling requirements of theservice flow and convergence sublayer parameters encodings specifyingconvergence sublayer specific parameters. In this case, the service flowparameters comprise a link indicator indicating whether parameters forthe MAC PDU transmission is uplink or a downlink and the MAC header typeparameter.

Preferably, The AAI_DSA-RSP message comprises service flow parametersspecifying traffic characteristics and scheduling requirements of theservice flow and convergence sublayer parameters encodings specifyingconvergence sublayer specific parameters. In this case, the service flowparameters comprises a link indicator indicating whether parameters forthe MAC PDU transmission is uplink or a downlink and the MAC header typeparameter.

The small data packet of the present invention may be a voice overinternet protocol (VoIP) data packet which has a predetermined fixedsize with a predetermined periodicity.

Preferably, the SPMH consists of the flow identifier (FID) field, anextended header group presence indicator (EH) field, a length field anda sequence number (SN) field. In this case, the FID field identifies theconnection used for the transmission of the MAC PDU; the EH fieldindicates whether an extended header group is present following theSPMH; the length field indicates a length in bytes of the MAC PDUincluding the SPMH and an extended header if present; and the SN fieldindicates a payload sequence number of the MAC PDU and increments by onefor each MAC PDU.

The SN field is used for an HARQ (hybrid-automatic retransmissionrequest) scheme.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

ADVANTAGEOUS EFFECTS OF INVENTION

Accordingly, the present invention provides the following effects oradvantages.

First of all, the present invention performs communications moreefficiently in a manner that information on a MAC header type is sharedin the course of a service connection between a base station and amobile station.

Secondly, the present invention uses a compact MAC header (i.e. SPMH)including sequence number (SN) information necessary for performing HARQreordering on such a small packet as VoIP, thereby reducing a MAC headeroverhead according to a presence of an extended header.

Thirdly, a flow identifier (Flow ID) for identifying a correspondingservice flow is included in a compact MAC header, whereby a receivingend receiving the compact MAC header is able to reduce a processingoverhead generated from a flow mapping process.

Finally, the present invention is able to provide a more efficientservice by sharing of information on a type of a MAC head to be used fora MAC PDU, which is to be transmitted next, in the course of a serviceconnection between a base station and a mobile station for MAC PDUtransmission.

It is to be understood that the effects that can be obtained by thepresent invention are not limited to the aforementioned effects, andanother effects, which are not described, will be apparent to thoseskilled in the art to which the present invention pertains, from thefollowing detailed description of the present invention.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a diagram for one example of an internet protocol stack usedin general;

FIG. 2 is a diagram for operation of each layer for data transmissionused in general;

FIG. 3 is a diagram of a layer structure of a general IEEE 802.16system;

FIG. 4 is a diagram of a connection and service flow (SF) used by anIEEE 802.16 system;

FIG. 5 is a diagram for one example of a MAC PDU (protocol data unit)type defined in a wireless MAN mobile communication system based on IEEE802.16 system used in general;

FIG. 6 is a diagram for one example of a compact MAC header structureaccording to one embodiment of the present invention;

FIG. 7 is a diagram for one example of a process for a mobile station toperform a service connection for MAC PDU transmission to a base stationaccording to another embodiment of the present invention;

FIG. 8 is a diagram for one example of a process for a base station toperform a service connection for MAC PDU transmission to a mobilestation according to another embodiment of the present invention;

FIG. 9 is a diagram for another example of a process for a mobilestation to perform a service connection for MAC PDU transmission to abase station according to another embodiment of the present invention;

FIG. 10 is a diagram for another example of a process for a base stationto perform a service connection for MAC PDU transmission to a mobilestation according to another embodiment of the present invention;

FIG. 11 is a diagram for one example of a MAC PDU generating unit in atransmitting device according to another embodiment of the presentinvention; and

FIG. 12 is a block diagram for describing a mobile station and a basestation according to a further embodiment of the present invention forperforming the above described embodiments of the present invention.

MODE FOR THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

The present invention relates to MAC headers for efficient datatransmissions in a wireless communication system.

First of all, the following embodiments correspond to combinations ofelements and features of the present invention in prescribed forms. And,it is able to consider that the respective elements or features areselective unless they are explicitly mentioned. Each of the elements orfeatures can be implemented in a form failing to be combined with otherelements or features. Moreover, it is able to implement an embodiment ofthe present invention by combining elements and/or features together inpart. A sequence of operations explained for each embodiment of thepresent invention can be modified. Some configurations or features ofone embodiment can be included in another embodiment or can besubstituted for corresponding configurations or features of anotherembodiment.

In the description of drawings, procedures or steps, which may ruin thesubstance of the present invention, are not explained. And, proceduresor steps, which can be understood by those skilled in the art, are notexplained as well.

In this disclosure, embodiments of the present invention are describedcentering on the data transmission/reception relations between a basestation and a mobile station. In this case, the base station ismeaningful as a terminal node of a network which directly performscommunication with the mobile station. In this disclosure, a specificoperation explained as performed by a base station can be performed byan upper node of the base station in some cases.

In particular, in a network constructed with a plurality of networknodes including a base station, it is apparent that various operationsperformed for communication with a mobile station can be performed by abase station or other networks except the base station. In this case,‘base station’ can be replaced by such a terminology as a fixed station,a Node B, an eNode B (eNB), an advanced base station (ABS), an accesspoint and the like. And, ‘mobile station (MS)’ can be replaced by such aterminology as a user equipment (UE), a subscriber station (SS), amobile subscriber station (MSS), an advanced mobile station (AMS), amobile terminal, a terminal and the like.

Moreover, a transmitting end means a stationary and/or mobile node thattransmits a data service or a speech service. And, a receiving end meansa stationary and/or mobile node that receives a data service or a speechservice. Hence, a mobile station can become a transmitting end and abase station can become a receiving end, in uplink. Likewise, a mobilestation becomes a receiving end and a base station can become atransmitting end, in downlink.

In particular, the steps or parts, which are not explained to clearlyreveal the technical idea of the present invention, in the embodimentsof the present invention can be supported by the above documents.Specifically, embodiments of the present invention can be supported byat least one of P802.16-2004, P802.16e-2005, P802.16e-2009 and P802.16mdocuments, which are the standards of IEEE 802.16 system.

In the following description, a preferred embodiment of the presentinvention is explained in detail with reference to the accompanyingdrawings. Detailed description disclosed together with the accompanyingdrawings is intended to explain not a unique embodiment of the presentinvention but an exemplary embodiment of the present invention.

In the following description, specific terminologies used forembodiments of the present invention are provided to help theunderstanding of the present invention. And, the use of the specificterminology can be modified into another form within the scope of thetechnical idea of the present invention.

FIG. 4 is a diagram of a connection and service flow (SF) used by anIEEE 802.16 system.

Referring to FIG. 4, in order to provide QoS of an upper service flow(SF), a logical connection of a MAC layer maps an SF to a logicalconnection for which a QoS parameter is defined. And, the logicalconnection is defined to provide QoS in a MAC layer through appropriatescheduling for data transmission of the corresponding connection. Typesof connections defined in the MAC layer include a management connection(or, a control connection) allocated per mobile station for mobilestation management in the MAC layer and a transport connection mapped toa service flow for upper service data transport.

All user data communications are in the context of transportconnections. A transport connection is uni-directional, and identifiedby a unique flow identifier (FID) which is assigned during a DSAprocedure (will be described hereinafter), excluding the transportconnections associated with the default service flows. The transportconnections for the default service flows in uplink and downlinkdirection are each identified by the pre-assigned FID and established bythe registration procedure during network entry.

Each transport connection is associated with an active or admittedservice flow to provide various levels of QoS required by the serviceflow. The transport connection is established when the associated activeservice flow is admitted or activated, and released when the associatedservice flow becomes inactive. Once established, the FID of thetransport connection is not changed during wireless MAN-OFDMA advancedsystem handovers. To reduce bandwidth usage, the AMS and the ABS mayestablish/change/release multiple connections using a single DSx messagetransaction on a control connection.

Service flows can be pre-provisioned or dynamically created. Transportconnections associated with pre-provisioned service flow are establishedby the DSA procedure triggered by completion of the MAS network entry.Especially the transport connections associated with the default serviceflows in uplink and downlink direction each are established with thepre-assigned FIDs by successful registration procedure.

On the other hand, AMS or ABS can create new service flows and theirassociated transport connections dynamically using DSA procedure ifneeded. A transport connection is created, changed or deleted when theassociated service flow is created, changed or deleted respectively.

FIG. 5 is a diagram for one example of a MAC PDU (protocol data unit)type defined in a wireless MAN mobile communication system based on IEEE802.16 system used in general.

In general, in a link layer below a second layer (i.e., a link layer ora MAC layer) and a physical layer, a header format of MAC PDU is defineddifferent according to a protocol of such a system as LAN, Wireless LAN,3GPP, 3GPP2, Wireless MAN and the like. MAC header contains a MAC orlink address of a node for inter-node data forwarding in the link layerand is able to contain header error check and link layer controlinformation.

Referring to FIG. 5, each MAC PDU starts with a MAC header of apredetermined length. The MAC header is located ahead of a payload ofthe MAC PDU. The MAC PDU can include an extended header group whichcomprising at least one extended header. The extended header is locatedbehind the MAC header. In case that the extended header group isincluded, the payload is located behind the extended header group. Thepayload of the MAC PDU can include at least one subheader, a MAC SDU anda fragment. And, a length of payload information is changeable torepresent a variable byte size. Accordingly, the MAC sublayer is able totransmit various traffic types of an upper layer without recognizing aformat or bit pattern of a message. Besides, a cyclic redundancy check(CRC) for error detection can be included in the MAC PDU [not shown inFIG. 5].

There are MAC headers of three types. In particular, they can beclassified into an advanced generic MAC header (AGMH) including apayload behind a header, a compact MAC header (CMH) for supporting suchan application as VoIP, and a MAC signaling header for such a control asa bandwidth request and the like. Hereinafter, the CMH can be referredto as short-packet MAC header (SPMH).

The AGMH having the payload located behind the header is located at astart part of DL/UL MAC PDU including data of a MAC control message anda convergence layer (CS) and is called a generic MAC header (GMH) inIEEE 802.16e and the like.

Table 1 shows one example of an advanced generic MAC header (AGMH)structure used in a wireless communication system based on IEEE 802.16system.

TABLE 1 Size Syntax (bit) Notes Advanced Generic MAC header( ){ Flow ID4 Flow Identifier EH 1 Extended header group presence indicator; Whenset to ‘1’, this field indicates that an Extended Header group ispresent following this GMH. Length 11 This field indicates the length inbytes of MAC PDU including the AGMH and extended header if present. EHis set to ‘1’, this represent the 11 LSBs of 14 bit MAC PDU lengthotherwise it represents the 11 bit MAC PDU length. }

Referring to Table 1, an AGMH includes a flow identifier (Flow ID) fieldhaving a flow identifier for identifying a service flow carrying MAC PDUusing the corresponding AGMH from other service flows, an extendedheader presence indicator field (EH presence indicator) indicatingwhether an extended header of the corresponding MAC PDU is present, anda length field (Length) including length information of thecorresponding MAC PDU.

When the extended header presence indicator field is set to ‘1’, thisfield indicates that at least one extended header is present at the MACPDU. If the corresponding field is set to ‘0’, this field indicates thatthe extended header is not present. The length field (Length) indicateslength information of the MAC PDU including the extended header if theextended header is present. The length field is represented in bytes.And, 11 bits are allocated to the length field. When the EH field is setto ‘1’, the length field represents the 11 LSBs of 14 bit MAC PDU lengthotherwise it represents the 11 bit MAC PDU length.

The short-packet MAC header (SPMH) is generated to have a size equal toor smaller than a predetermined size with predetermined periodicity likeVoIP. And, the compact MAC header is usable if an application, to whichARQ (automatic retransmission request) is not applied, is supported.

Table 2 shows one example of a format of SPMH used in a wirelesscommunication system based on IEEE 802.16 system.

TABLE 2 Size Syntax (bit) Notes Short- packet MAC header( ){ EH 1Extended header presence indicator; When set to ‘1’, this fieldindicates that an Extended Header is present following this SPMH. Length7 This field indicates the length in bytes of MAC PDU including the SPMHand extended header if present. }

Referring to Table 2, a SPMH includes an extended header presenceindication field indicating whether an extended header is present and alength field indicating a length of MAC PDU including a SPMH.

Since the SPMH is a header that is used at a resource allocatedlocation, which was already negotiated between a base station and amobile station, for such resource allocation as persistent resourceallocation and group resource allocation, a receiving side is able toidentify the SPMH at the corresponding location despite that a flowidentifier is not included. Unlike the AGMH, the SPMH does not include afield (Flow ID) including a flow identifier.

Since the persistent resource allocation or the group resourceallocation is used as a resource allocation scheme for such a periodicand short packet as VoIP, a length of the SPMH can be implemented withina 7-bit range according to a VoIP packet size. Therefore, the compactMAC head, as exemplarily shown in Table 2, can have a size of 1 byte byallocating 1 bit and 7 bits to the extended header presence indicatorfield and the length field, respectively.

Meanwhile, a MAC PDU can be accompanied by at least one extended headeraccording to property of information to be carried on the correspondingMAC PDU, a transmission scheme applied to the corresponding MAC PDU, orthe like. The extended header is inserted right behind the MAC header.In case that a corresponding MAC PDU includes a payload, an extendedheader is inserted in front of the payload.

The extended header is a subheader inserted behind a MAC header in MACPDU. Using an extended header presence indicator field of an AGMH or aSPMH, a receiving side can be informed whether the header is included inthe MAC PDU. Yet, a MAC signaling header is not companied by an extendedheader.

Table 3 shows one example of a generic extended header used in awireless communication system based on IEEE 802.16 system.

TABLE 3 Size Syntax (bit) Notes Extended Header( ){ LAST 1 Last ExtendedHeader indicator: 0 = one or more extended header flows the currentextended header unless specified otherwise; 1 = this extended header isthe last extended header unless specified otherwise Type TBD Type ofextended header Body Variable Type dependent content Contents }

Referring to Table 3, an extended header includes an extended headerpresence indicator field (LAST) indicating whether at least one or moreother extended headers are present behind the corresponding extendedheader, an extended header type field (Type) indicating a type of thecorresponding extended header and an extended header body field (BodyContents) including at least one field having informations relevant tothe extended header indicated by the extended header type field.

When 1 bit is allocated to the extended header indicator field (LAST),for example, if the corresponding field is set to 0, it indicates thatthe at least one or more other extended headers are present behind thecurrent extended header. If the corresponding field is set to 1, it isable to indicate that the current extended header is the extended headerincluded last in the corresponding MAC PDU.

In the extended header body field (Body Contents), the includedinformation and a length of the body field are determined according toan extended header type indicated by the extended header type field(Type).

The extended header types are described with reference to Table 4 asfollows.

Table 4 shows types of a generic extended header used in a wirelesscommunication system based on IEEE 802.16 system.

TABLE 4 Extended header type Notes Fragmentation and This extendedheader is used in applying Packing Extended fragmentation, packing orsequence number Header to MAC PDU accompanied by a payload for a singletransport connection. MAC Control This extended header is used when MACPDU Extended Header includes a payload for a control connection.Multiplexing This extended header is used when a Extended Header payloadfor multiplexing association related to the same SA (securityassociation) multiplexed in the same MAC PDU is included. Message ACKThis extended header is used for a base Extended Header station or amobile station to indicate acknowledgement of a MAC control message.Sleep Control This extended header is used for a base Extended Headerstation or a mobile station to deliver control signaling related to asleep cycle operation. Correlation This extended header is used by amobile Matrix Feedback station in response to feedback polling ExtendedHeader A-MAP IE for requesting a quantized transport correlation matrixwhen a base station uses 2 or 4 transmitting antennas. MIMO FeedbackThis extended header is used by a mobile Extended Header station inresponse to feedback polling A-MAP IE fore requesting a feedback ofbroadband or subband information. Piggybacked This extended header isused when a Bandwidth Request mobile station requests a piggybackedExtended Header bandwidth for at least one flow. MAC PDU Length Thisextended header is added to a Extended Header corresponding MAC PDU if aMAC PDU length is equal to or greater than 2,047 bytes. ARQ FeedbackThis extended header is used when an ARQ Extended Header receiving parttransmits feedback information.

Regarding a plurality of the extended headers described with referenceto Table 4, if a MAC PDU accompanied by a payload for a single transportconnection is going to be fragmented, packed or ARQ-applied, FPEH ispresent at the corresponding MAC PDU. In doing so, an AGMH is used as aMAC header. Although fragmentation, packing, ARQ or the like is notapplied, in that HARQ reordering is applied to such a small data packetas VoIP, MAC PDU can be accompanied by FPEH to include sequence numberinformation on a packet to retransmit. In this case, a SPMH is used as aMAC header.

Table 5 shows one example of a fragmentation & packing extended header(FPEH) format used in a wireless communication system based on IEEE802.16 system. And, fields included this format are described withreference to Table 5 as follows.

TABLE 5 Size Syntax (bit) Notes FPEH( ){ RI (Rearrangement 1 This fieldincludes ARQ rearrangement header Indicator) indicator. ‘0’ bitsetting - Not indicate ARQ rearrangement ‘1’ bit setting - Indicate ARQrearrangement SN(Sequence 10 ‘SN’ is maintained by connection unit.Number) Regarding non-ARQ connection, ‘SN’ indicates a sequence numberof MAC PDU containing a payload and a value of the SN is incremented perMAC PDU by 1. Regarding ARQ connection, ‘SN’ indicates an ARQ blocksequence number. FC (fragment 2 This field includes information onControl) fragmentation control AFI (ARQ Feedback 1 This field includesARQ feedback IE) information element (IE) indicator. ‘0’ bit setting:ARQ feedback IE is not included in MAC PDU ‘1’ bit setting: ARQ feedbackIE is present behind FPEH AFP (ARQ Feedback 1 This field includes ARQfeedback poll Poll) indicator. ‘0’ bit setting: ARQ feedback poll is notincluded ‘1’ bit setting: ARQ feedback poll relevant to a connectionindicated by a generic MAC header (GMH) is included If(RI=1){ LSI (LastARQ 1 Last ARQ subblock indicator Subblock ‘0’ bit setting: Lastsubblock in Indicator) single ARQ block not included in a correspondingMAC PDU is indicated ‘1’ bit setting: Single ARQ block included in acorresponding MAC PDU SSN (Sub-SN) TBD Sub-sequence number of 1^(st) ARQsubblock } Do{ End 1 Indication of more information ‘0’ bit setting:‘Length’ field and other ‘End’ field are further included ‘1’ bitsetting: ‘Length’ field and other ‘End’ field are not further includedIf(End=0){ Length 11 This field indicates the length of SDU or SDUfragment } while (!End) Reserved variable } }

Referring to Table 5, a sequence number field (SN) included in FPEHindicates a sequence number of MAC PDU accompanied by a payload in casethat the FPEH is not used for ARQ connection. The sequence number field(SN) is incremented by 1 for each MAC PDU. In case that the FPEH is usedfor the ARQ connection, the sequence number field is set to a prescribedvalue that indicates a sequence number of an ARQ block.

If the rearrangement header identifier field (RI) in the FPEH is set to0 and the end field (End) indicating whether more information isincluded is set to 0, the fragmentation & packing extended header has alength of at least 2 bytes. In case of attempting to transmit data, theFPEH can present at a MAC PDU including a generic MAC header and a SPMHfor HARQ reordering of VoIP packet.

In this case, SDU including a SPMH is used for such a periodicallytransmitted small packet as VoIP packet and the like. In this case,fragmentation, packing ARQ or the like is not performed on such a packetas VoIP and the FPEH uses the SN field only for HARQ reordering. Sincethe VoIP packet is generated to have a size smaller than that of otherdata with a prescribed periodicity, it is not necessary to allocate aconsiderable bit size to the SN field. Even if the FPEH of a minimumsize (e.g., 2 bytes) is added to a VoIP packet including a SPMH, a sizeof the header becomes 3 bytes to result in unnecessary resource waste inVoIP packet transmission.

As mentioned in the foregoing description, a SPMH is used at a resourceallocated location previously negotiated between a base station and amobile station and does not include a field Flow ID to reduce atransmission overhead. Occasionally, when a base station or a mobilestation receives a MAC PDU including a SPMH, it is necessary to performa flow mapping process. For instance, in case of using a multiplepersistent allocation (PA) or a group resource allocation, a base/mobilestation should perform mapping on a corresponding flow in each resourceallocation to be aware that each resource allocation is mapped to whichservice. In case of receiving a SPMH not including the field Flow ID ateach corresponding location, the base/mobile station should perform aflow mapping process to increase a processing overhead.

Therefore, the present invention intends to propose a method oftransmitting a signal using an efficient SPMH structure or format usablein transmitting such a small packet transmitted with a prescribedperiodicity as a VoIP packet. And, the present invention also intends topropose a method of providing a service through a step of negotiating aMAC header type between a base station and a mobile station.

FIG. 6 is a diagram for one example of a SPMH structure according to oneembodiment of the present invention.

In the following disclosure including FIG. 6, a single scale mark of ablock representing a MAC PDU structure indicates 1 bit and a horizontalrow indicates 1 byte. Moreover, bits are arranged downward in order froma most significant bit (MSB) to a least significant bit.

Referring to FIG. 6, a SPMH according to one embodiment of the presentinvention includes a flow identifier (Flow ID) field 601 having anidentifier of a service flow, an extended header group presenceindicator (EH) field 602 indicating whether an extended header groupcomprising at least one extended header is present behind the SPMHimmediately, a length (Length) field 603 having length information of acorresponding MAC PDU, and a sequence number (SN) field 604 indicating asequence number. The respective fields are schematically described withreference to Table 6 as follows.

Table 6 shows one example of a SPMH format according to one embodimentof the present invention.

TABLE 6 Size Syntax (bit) Notes Short-packet MAC Header( ){ Flow ID 4Flow Identifier EH 1 Extended Header group presence indicator Length 7This field indicates the length in bytes of MAC PDU including the SPMHand extended header if present. Sequence 4 This field indicates a MACPDU Number(SN) payload sequence number incremented by one for each MACPDU }

Referring to FIG. 6 and Table 6, a SPMH according to one embodiment ofthe present invention includes a 4-bit flow identifier field (Flow ID),a 1-bit extended header presence indicator field (EH), a 7-bit lengthfield (Length) capable of supporting 127-byte MAC PDU, and a 4-bitsequence number field (SN). In this case, a size of the SPMH can beimplemented with 2 bytes.

The flow identifier (FID) field 601 includes identification informationof a service flow used by the corresponding SPMH.

The sequence number (SN) field 604 indicates sequence number informationcorresponding to a payload of the MAC PDU. In particular, since the SPMHis used in transmitting such a small packet generated with prescribedperiodicity as VoIP packet, it is able to apply HARQ to an error checkinstead of applying ARQ thereto. Therefore, unlike the sequence numberfield included in the above FPEH described with reference to Table 5,the sequence number field of the SPMH includes a sequence number of theMAC PDU accompanied by the payload in case of not applying the ARQ. Inthis case, the bit value, to which the sequence number field is set, isincremented by 1 for each MAC PDU.

The SN field of the SPMH is used for HARQ reordering. If a maximum HARQretransmission count in the IEEE 802.16m system is basically 4 and amaximum interval between retransmitted HARQs is 2 frames, a maximum timetaken for the HARQ retransmissions is 8 frames in general. Assuming thatthe generation periodicity of VoIP packet is minimum 2 frames, when a4-bit sequence number is used, it is less probable that the HARQretransmission is not completed within 32 frames.

Therefore, a SPMH according to one embodiment of the present inventionis able to simplify a size of the SPMH including a sequence number fieldby small bit allocation in a manner of allocating 4 bits to the sequencenumber field rather than allocating 10 bits to a sequence number fieldof FPEH.

In case of applying HARQ to a corresponding MAC PDU, the MAC PDU whichincludes SPMH may not be accompanied by FPEH. Therefore, it is able toreduce a size of over head of a MAC header into minimum 2 bytes, asshown in FIG. 6. In this case, it is able to use the extended headergroup presence indicator field 602 to indicate whether an extendedheader is present or not.

Thus, in case that a MAC PDU is transmitted using a SPMH according toone embodiment of the present invention or the AGMH described withreference to Table 1, a base station and a mobile station is able toperform negotiation about a of a MAC header type prior to MAC PDUtransmission.

In particular, according to another embodiment of the present invention,a base station and a mobile station is able to previously negotiate touse either an AGMH or a SPMH according to a type or property of a packetto transmit, information to transmit and a transmission scheme used forpacket transmission. This negotiation procedure can be performed via aMAC control message between a base station and a mobile station. In thiscase, MAC control messages available for the negotiation procedureinclude a dynamic service addition request/response message (e.g.Advanced Air Interface_Dynamic Service Addition-Request/Response:AAI_DSA-REQ/RSP), an advanced air interface dynamic service changerequest/response message (Advanced Air Interface Dynamic ServiceChange-Request/Response: AAI_DSC-REQ/RSP) and the like for example

In the following description, another embodiment of the presentinvention is explained on the assumption that a information on a MACheader type is shared using a dynamic service addition request/responsemessage between a base station and a mobile station.

FIG. 7 is a diagram for one example of a process for a mobile station toperform a service connection for MAC PDU transmission to a base stationaccording to another embodiment of the present invention.

Referring to FIG. 7, a mobile station (AMS) sends AAI_DSA-REQ to a basestation to create a new service flow and a corresponding connection[S701].

In this case, the AAI_DSA-REQ sent to request the dynamic service flowgeneration can include parameters shown in Table 7 for example.

TABLE 7 Parameters in AAI_DSA-REQ Notes Control Message Type Typeinformation of AAI_DSA-REQ message Service Flow parameters Service flowparameters for specifying traffic properties and scheduling requirementsof service flow (cf. Table 8) CS parameter encodings This field includesa parameter specified to a convergence sublayer in a correspondingservice flow. SCID Sleep cycle setting change (included in AAI_DSA-REQsent by a base station or AAI_DSA-RSP sent by a base station in responseto a request made by a mobile station) Predefined BR Index Indexinformation used for a preset bandwidth request procedure (included inAAI_DSA- REQ sent by a base station or AAI_DSA-RSP sent by a basestation in response to a request made by a mobile station) E-MBS serviceParameter for requesting a presence or non-presence of amulticast/broadcast service (yet, this field is included in AAI_DSA-REQsent by a mobile station only)

Referring to Table 7, various parameters for a dynamic service additionrequest are included in AAI_DSA-REQ. And, MAC header type informationrelated to one embodiment of the present invention can be included in aservice flow parameter among the various parameters.

Table 8 shows various parameters included in service flow parameters. Inaddition, the service addition request/response (AAI_DSA-REQ/RSP)messages can further include various service flow parameters omittedfrom Table 8.

TABLE 8 Size Fields (bits) Description Flow ID 4 Service flow IDinformation UL/DL 1 This field includes an indicator Indicatorindicating whether a link related to corresponding parameter is uplinkor downlink . . . . . . . . . MAC Header 1 This field indicates whetherAGMH or Type SPMH is present at the start of MAC PDUs of a correspondingservice flow. 0 = AGMH 1 = SPMH

Referring to Table 8, a service flow parameter can include an identifier(Flow ID) for a service flow to be used in the future, anuplink/downlink indicator (UL/DL Indicator) indicating thatcorresponding parameters are used in either uplink or downlink.

The flow identifier specifies a connection which is associated with aservice flow to the mobile station.

In case that a base station (ABS) sends AAI_DSA-REQ message (i.e. ABSinitiated), a flow identifier can be included in the AAI_DSA-REQ. Inother case that a mobile station (AMS) sends AAI_DSA-REQ (i.e., AMSinitiated), as shown in FIG. 7, a flow identifier can be included inAAI_DSA-RSP message sent by a base station in response to theAAI_DSA-REQ message.

A MAC header type parameter indicates which one of an AGMH and a SPMH isused for a corresponding MAC PDU of the service flow. For instance, when1 bit is allocated to the MAC Header Type parameter, if the MAC headertype parameter is set to ‘0’, it indicates that an AGMH is used. If theMAC header type parameter is set to ‘1’, it indicates that a SPMH isused.

Yet, the meaning indicated according to the bit setting at the MACheader type parameter is just one example for describing the presentinvention. Regarding the type information according to the bit valuesetting corresponding to the MAC header type field, the meaningsindicated by the ‘0’ and ‘1’ bit settings can be switched to each other.

Referring now to FIG. 7, the mobile station is able to send AAI_DSA-REQmessage including a parameter (MAC Header Type=1) about a MAC headertype for specifying a use of a SPMH to the base station in order totransmit such a small packet generated with prescribed periodicity asVoIP. In this case, the AAI_DSA-REQ can further include the UL/DLindicator indicating parameters are for an uplink.

Having received the AAI_DSA-REQ message, the base station sends

AAI_DSA-RSP message to the mobile station in response to the receivedAAI_DSA-REQ message [S702].

In particular, parameters included in the AAI_DSA-RSP are described withreference to Table 9 as follows.

TABLE 9 Parameters in AAI_DSA-RSP Notes Control Message Type Typeinformation of AAI_DSA- RSP message Confirmation Code (CC) Confirmationcode for the corresponding AAI_DSA- REQ Service Flow parameters Serviceflow parameters for specifying traffic properties and schedulingrequirements of service flow (cf. Table 8) CS parameter encodings Thisfield includes a parameter specified to a convergence sublayer in acorresponding service flow. SCID Sleep cycle setting change (included inAAI_DSA-REQ sent by a base station or AAI_DSA-RSP sent by a base stationin response to a request made by a mobile station) Predefined BR IndexIndex information used for a preset bandwidth request procedure(included in AAI_DSA- REQ sent by a base station or AAI_DSA-RSP sent bya base station in response to a request made by a mobile station) FID(Flow ID) This field indicates Flow ID information on a transportconnection included if a service flow is successfully added. QoSparameters QoS parameter relevant to service classification E-MBSservice/E-MBS Zone This field indicates ID ID/E-MBS service Flowinformation of E-MBS zone and parameters service flow parameter about E-MBS if E-MBS is supported.

Referring to Table 9, AAI_DSA-RSP message includes prescribedparameters. And, a type of each of the included parameters is determinedaccording to a transmitting subject. AAI_DSA-RSP type information, aconfirmation code for AAI_DSA-REQ, a service flow parameter and aparameter specified to a CS in a corresponding service flow may beincluded in the AAI_DSA-RSP message sent by a base station or a mobilestation.

According to the sent AAI_DSA-REQ message, in case that a service flowgeneration is successfully performed, parameters relevant to SCID,Predefined BR index, FID, E-MBS service and the like can be furtherincluded in the AAI_DSA-RSP message.

The service flow parameter is further included in the AAI_DSA-RSPmessage as well. Since the AAI_DSA-RSP message includes the sameinformation described with reference to Table 8, the redundantdescription shall be omitted from the following description. Yet,regarding information on a MAC header type, a MAC header type parameteridentical to that included in the AAI_DSA-REQ message or MAC header typeinformation arbitrarily determined by the base station can be includedin the AAI_DSA-RSP message sent by the base station in response to arequest made by the mobile station. In case that the mobile stationsends AAI_DSA-RSP message in response to the AAI_DSA-REQ message sent bythe base station. The MAC header type parameter can be also included inthe AAI_DSA-RSP message.

In FIG. 7, since the base station sends the MAC header type parameterindicating the use of the SPMH via the AAI_DSA-RSP message in the stepS702, it can be regarded as performing the negotiation on the SPMH usebetween the base station and the mobile station.

Having received the AAI_DSA-RSP, the mobile station sends AAI_DSA-ACKindicating acknowledgement of the response message to the base station[S703]. Thus, the service generation request procedure is completed touse the SPMH in uplink and an uplink service connection is established.

Afterwards, the mobile station is able to communicate (i.e.,transmitting and/or receiving) with the base station using MAC PDUs ofthe service flow. In this case, the MAC PDUs comprising a MAC headerindicated by the MAC header type field (i.e. SPMH) [S704]. In doing so,the SPMH used by the mobile station can include the generic SPMHdescribed with reference to Table 2 or the SPMH configured according toone embodiment of the present invention (See, FIG. 6).

FIG. 8 is a diagram for one example of a process for a base station toperform a service connection procedure for MAC PDU transmission to amobile station according to another embodiment of the present invention.

Referring to FIG. 8, in order to perform a downlink data transmission, abase station (ABS) sends AAI_DSA-REQ message requesting a new serviceflow generation to a mobile station (AMS) [S801].

In the AAI_DSA-REQ (ABS-initiated AAI_DSA-REQ) initiated by the basestation, the QoS parameter and FID on the corresponding service flow andthe like, which are described with reference to Table 9, can beincluded. Moreover, various parameters described with reference to Table7 and Table 9 are included in the AAI_DSA-REQ message. And, a MAC headertype parameter to be used can be included in a MAC PDU to betransmitted. For instance, in case that the base station attempts totransmit such a packet as VoIP to the mobile station, a MAC header typeparameter is set to 1 bit and a field including a link indicator can beset to a bit for indicating ‘downlink’.

Having received the AAI_DSA-REQ message, the mobile station sendsAAI_DSA-RSP message to the base station in response to the receivedAAI_DSA-REQ [S802].

Likewise, the AAI_DSA-RSP can include the former parameters describedwith reference to Table 9. Yet, the MAC header type parameter includedin the AAI_DSA-RSP sent by the mobile station is set to indicate thesame MAC header type included in the AAI_DSA-REQ.

The base station sends AAI_DSA-ACK for the AAI_DSA-RSP to the mobilestation [S803], thereby establishing a downlink service connection usingthe SPMH.

Afterwards, the base station is able to communicate (i.e., transmittingand/or receiving) with the mobile station using MAC PDUs of the serviceflow. In this case, the MAC PDUs comprising a MAC header indicated bythe MAC header type field (i.e. SPMH)[S804].

In doing so, the SPMH can be referenced to the generic compact MACheader described with reference to Table 2 or the SPMH configuredaccording to one embodiment of the present invention (see, FIG. 6).

FIG. 9 and FIG. 10 are flowcharts other examples of a process fortransmitting a signal according to one embodiment of the presentinvention. In particular, a process for transmitting a signal using anAGMH is shown.

FIG. 9 is a diagram for another example of a process for a mobilestation (AMS) to perform a service connection for MAC PDU transmissionto a base station (ABS) according to another embodiment of the presentinvention, which corresponds to the former signal transmitting processdescribed with reference to FIG. 7. Specifically, steps S901 to S904shown in FIG. 9 correspond to the former steps S701 to S704 shown inFIG. 7, respectively. Yet, a MAC header type parameter included inAAI_DSA-REQ/RSP messages of the step S901/S902 can be set to ‘0’ toindicate a use of an advanced generic MAC header (AGMH) according to theexample shown in Table 4.

After a service connection has been established, a MAC PDU transmittedin uplink in the step S904 uses the generic MAC header (AGMH)exemplarily shown in Table 1 and is accompanied by the fragmentation &packing extended header (FPEH) described with reference to Table 5 forthe VoIP packet transmission. In case that a fragmentation & packingextended header (FPEH) is present, an extended header presence indicatorfield of the AGMH can be set to ‘1’. Hence, the corresponding MAC PDUuses an AGMH of minimum 2 bytes and a MAC header of minimum 4 bytes inuse of FPEH of minimum 2 bytes.

FIG. 10 is a diagram for another example of a process for a base stationto perform a service connection for MAC PDU transmission to a mobilestation according to another embodiment of the present invention, whichcorresponds to the former signal transmitting process described withreference to FIG. 8. Specifically, steps S1001 to S1004 shown in FIG. 10correspond to the former steps S801 to S804 shown in FIG. 8,respectively. And, the description of a MAC header type parameterindicating a use of an AGMH is the same as described with reference toFIG. 9.

In case of using a SPMH or an AGMH according to one embodiment of thepresent invention, a mobile station receives a MAC PDU including thecorresponding MAC header, identifies a connection which is associatedwith a service flow via ‘Flow ID’ included in AAI_DSA-REQ message, andthen obtains MAC header information of the MAC header used by thecorresponding service flow. Therefore, the mobile station confirms a MACheader used by a corresponding flow via ‘Flow ID’ of a MAC headerincluded in a next-transmitted MAC PDU and is then able to perform aprocessing process on the corresponding MAC PDU.

Moreover, in case of using a SPMH in a prescribed length (e.g., 2 bytes)including a sequence number according to one embodiment of the presentinvention, as shown in FIG. 6, a separate FPEH needs not to be present.Therefore, it is able to reduce a MAC header overhead.

The MAC header type negotiation procedures performed via AAI_DSA-REQ/RSPin the embodiments of the present invention described with reference toFIGS. 7 to 10 are identically applicable to a procedure performed incase of changing a dynamic service flow. In this case, a base stationand a mobile station enable indication information on a MAC header typeto be included as a service flow parameter in the course of exchangingAAI_DSC-REQ/RSP messages.

Besides, a SPMH including a sequence number (SN) field according to oneembodiment of the present invention can be implemented in various typeswithin a prescribed length.

In the following description, one example of a transmitting device (or,transmitting end) for generating a MAC PDU including a MAC header (e.g.SPMH or AGMH) according to one of embodiments of the present inventionis described with reference to FIG. 11 as follows.

FIG. 11 is a diagram for one example of a MAC PDU generating unit in atransmitting device according to another embodiment of the presentinvention. In particular, FIG. 11 shows a process for constructing MACPDU used for ARQ connection, non-ARQ connection or control connection.

Referring to FIG. 11, a MAC PDU generating unit in a transmitting endcan include a MAC control module 1101, a convergence sublayer 1102 and aMAC PDU generating module 1103.

MAC control messages generated from the MAC control module 1101 arefragmented into MAC PDU accompanied by a payload and can be thendelivered to the MAC PDU generating module 1103. Moreover, controlinformation required for generating a signaling header can betransmitted to the MAC PDU generating module 1103 as well.

The convergence sublayer 1102 performs a function of converting ormapping data, which is to be transmitted, to MAC SDU. In particular, theconvergence sublayer 1102 classifies MAC SDUs into a MAC SDU to transmitand a transmitted MAC SDU. Once related to a specific MAC connection, atleast one upper layer PDU should be compressed into a type of MAC SDU.This SDU to enter a network can be classified by the convergencesublayer 1102 into at least one set according to a prescribed mappingreference. The convergence sublayer is able to perform headercompression on at least one header included in the generated MAC SDU.The convergence sublayer 1102 delivers the MAC SDU to transmit to theMAC PDU generating module 1103 and is able to provide information (e.g.,length information, etc.) required for the header generation of the MACPDU to transmit as well.

The at least one MAC SDU generated by the convergence sublayer 1102 isconverted to a MAC PDU payload via fragmentation or packing. Theconverted at least one MAC PDU payload is then delivered to the MAC PDUgenerating module. In this case, the MAC PDU payload can be classifiedaccording to a case of applying ARQ or a case of not applying ARQ.

The MAC PDU generating module 1103 constructs MAC PDU including the MACPDU payload delivered from the MAC control module 1101 or theconvergence sublayer 1102 and is able to include a MAC header generatingunit and a multiplexer. In this case, a MAC header generated by the MACheader generating unit can include at least one of a generic MAC headerdescribed with reference to Table 1, a SPMH described with reference toTable 2 and a SPMH described with reference to FIG. 6.

Meanwhile, the multiplexer generates and outputs MAC PDU by multiplexingthe received MAC header and MAC SDUs received in order under the controlof the header generating unit.

In doing so, the MAC PDU generating module 1103 is able to performencryption on the MAC PDU. In particular, the MAC PDU generating module1103 further attaches PN and ICV to the generated MAC PDU or is able toattach CRC to the generated MAC PDU.

Afterwards, the generated MAC PDU is generated into at least onecontiguous MAC PDU, is delivered to a physical layer, and is thenexternally transmitted.

FIG. 12 is a block diagram for describing a mobile station and a basestation according to a further embodiment of the present invention forperforming the above described embodiments of the present invention.

First of all, a mobile station (AMS) works as a transmitting end inuplink and is able to work as a receiving end in downlink. A basestation (ABS) works as a receiving end in uplink and is able to work asa transmitting end in downlink. In particular, each of the mobilestation and the base station includes a transmitter and a receiver fortransmission of information and/or data.

Each of the transmitting end and the receiving end can include aprocessor, a module, a part and/or a means for performing embodiments ofthe present invention. In particular, each of the transmitting end andthe receiving end can include a module (means) for encrypting a message,a module for interpreting the encrypted message, an antenna forexchanging the message and the like.

Referring to FIG. 12, a left side indicates a configuration of atransmitting end, while a right side indicates a configuration of areceiving end. Each of the transmitting end and the receiving endincludes an antenna, a receiving module 1210/1220, a processor1230/1240, a transmitting module 1250/1260, and a memory 1270/1280.

The antenna includes a receiving antenna performing a function ofreceiving a radio signal externally and then delivering the receivedradio signal to the receiving module 1210/1220 and a transmittingantenna externally transmitting a signal generated from the transmittingmodule 1250/1260. In case that a multiple-antenna (MIMO) function issupported, at least two antennas can be provided.

The receiving module 1210/1220 reconstructs the radio signal receivedexternally via the antenna into original data in a manner of performingdecoding and demodulation on the received radio signal and is then ableto deliver the reconstructed original data to the processor 1230/1240.Alternatively, the receiving module and the antenna can be representedas a receiving unit configured to receive a radio signal instead ofbeing separated from each other, as shown in FIG. 12.

The processor 1230/1240 generally controls overall operations of themobile/base station. In particular, the processor 1230/1240 is able toperform a control function for performing the above-describedembodiments of the present invention, a MAC (medium access control)frame variable control function according to service characteristics andpropagation environment, a handover function, an authenticationfunction, an encryption function and the like.

The transmitting module 1250/1260 performs prescribed coding andmodulation on a signal and/or data, which is scheduled by the processor1230/1240 and will be then transmitted externally, and is then able todeliver the coded and modulated signal and/or data to the antenna.Alternatively, the transmitting module and the antenna can berepresented as a transmitting unit configured to transmit a radio signalinstead of being separated from each other, as shown in FIG. 12.

The memory 1270/1280 can store programs for processing and control ofthe processor 1230/1240 and is able to perform a function of temporarilystoring input/output data (e.g., in case of the mobile station, UL grantallocated by the base station, system information, station identifier(STID), a flow identifier (FID), an action time, region allocationinformation, frame offset information, etc.). And, the memory 1270/1280can include at least one of storage media including a flash memory, ahard disk, a multimedia card micro type memory, a memory card typememory (e.g., SD memory, XD memory, etc.), a RAM (random access memory),an SRAM (static random access memory), a ROM (read-only memory), anEEPROM (electrically erasable programmable read-only memory), a PROM(programmable read-only memory), a magnetic memory, a magnetic disk, anoptical disk and the like.

The processor 1230 of the transmitting end performs overall controloperations on the transmitting end and is able to include a MAC controlmodule 1231 configured to control a MAC layer for a service connectionto the receiving end and the like and a MAC PDU generating module 1232configured to generate MAC PDU.

The MAC control module 1231 generates a MAC control message forcontrolling a MAC layer and then controls the MAC layer through arelevant message exchange with the receiving end. In doing so, asmentioned in the foregoing description with reference to FIGS. 7 to 10,the MAC control module 1231 is able to generate a service connectionrequest message including a parameter of a MAC header type to be usedfor a corresponding service flow in case of a service connectionestablishment. In this case, the parameter of the MAC header type isdetermined by the MAC control module 1231 or can be determined based oninformation received from the MAC PDU generating module 1232. Moreover,since the MAC PDU generating module 1232 corresponds to the MAC PDUgenerating unit described with reference to FIG. 11, the redundantdescription shall be omitted from the following description.

The receiving end receives a service connection request message sent bythe transmitting end via the receiving module 1220 and then forwards thereceived message to the processor 1240.

The processor 1240 of the receiving end performs overall controloperations on the receiving end, determines whether to connect a serviceto the transmitting end in response to the received service connectionrequest message, and then generates a response message in response tothe received request message. Likewise, the processor 1240 is able toperform the procedures according to the embodiments of the presentinvention described with reference to FIGS. 7 to 10.

Moreover, the processor 1240 is able to include a signal processingmodule 1241 configured to perform processing on a signal received fromthe transmitting end. In this case, the signal processing module 1241 isable to perform a signal processing procedure on a received MAC PDUaccording to a MAC header type of each of the embodiments of the presentinvention.

A mobile station used for embodiments of the present invention caninclude a low-power RF/IF (radio frequency/intermediate frequency)module as well as the MAC PDU generating unit. And, the mobile stationcan include means, modules, parts and/or the like for performing acontroller function for performing the above-described embodiments ofthe present invention, a MAC (medium access control) frame variablecontrol function according to a service characteristic and electric waveenvironment, a handover function, an authentication and encryptionfunction, a packet modulation/demodulation function for datatransmission, a fast packet channel coding function, a real-time modemcontrol function, and the like.

A base station is able to transmit data received from an upper layer toa mobile station. The base station can include a low-power RF/IF (radiofrequency/intermediate frequency) module. And, the base station caninclude means, modules, parts and/or the like for performing acontroller function for performing the above-described embodiments ofthe present invention, an OFDMA (orthogonal frequency division multipleaccess) packet scheduling, TDD (time division duplex) packet schedulingand channel multiplexing function, a MAC (medium access control) framevariable control function according to a service characteristic andelectric wave environment, a fast traffic real-time control function, ahandover function, an authentication and encryption function, a packetmodulation/demodulation function for data transmission, a fast packetchannel coding function, a real-time modem control function, and thelike.

Industrial Applicability

Accordingly, the present invention is applicable to various wirelesscommunication systems.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents. And, it isapparently understood that an embodiment is configured by combiningclaims failing to have relation of explicit citation in the appendedclaims together or can be included as new claims by amendment afterfiling an application.

The invention claimed is:
 1. A method for communicating in a wirelessaccess system using a medium access control protocol data unit (MACPDU), the method comprising: receiving, by a mobile station (MS) from abase station (BS), a dynamic service addition request (AAI_DSA-REQ)message requesting to create a service flow, wherein the AAI_DSA-REQmessage comprises a first MAC header type parameter indicating a type ofa MAC header to be included in the MAC PDU of the service flow and aflow identifier (FID) identifying a connection associated with theservice flow; transmitting, by the MS to the BS, a dynamic serviceaddition response (AAI_DSA-RSP) message in response to the AAI_DSA-REQmessage, wherein the AAI_DSA-RSP message comprises a second MAC headertype parameter indicating the type of a MAC header to be included in theMAC PDU of the service flow; and communicating with the BS using the MACPDU comprising the MAC header indicated by the second MAC header typeparameter; wherein the second MAC header type parameter indicates one ofa generic MAC header (GMH) for general data packet transmission and ashort-packet MAC header (SPMH) for small data packet transmission and anon-ARQ connection, and wherein the SPMH consists of the flow identifier(FID) field identifying the connection used for the transmission of theMAC PDU, an extended header group presence indicator (EH) fieldindicating whether an extended header group is present following theSPMH, a length field indicating a length in bytes of the MAC PDUincluding the SPMH and an extended header if present, and a sequencenumber (SN) field indicating a payload sequence number of the MAC PDU,wherein the SN field increments by one for each MAC PDU, and wherein asize of the FID field is 4 bits, a size of the EH field is 1 bit, a sizeof the length field is 7 bits, and a size of the SN field is 4 bits, andwherein a total size of the SPMH is 2 bytes.
 2. The method according tothe claim 1, wherein the AAI_DSA-REQ message further comprises serviceflow parameters specifying traffic characteristics and schedulingrequirements of the service flow and convergence sublayer parametersencodings specifying convergence sublayer specific parameters.
 3. Themethod according to the claim 2, wherein the service flow parameterscomprise a link indicator indicating whether parameters for the MAC PDUtransmission are for an uplink or a downlink.
 4. The method according toclaim 2, wherein the small data packet is a voice over internet protocol(VoIP) data packet which has a predetermined fixed size with apredetermined periodicity.
 5. The method according to the claim 4,wherein the GMH consists of the flow identifier (FID) field, an extendedheader group presence indicator (EH) field, and a length field.
 6. Themethod according to claim 5, wherein the FID field identifies theconnection used for the transmission of the MAC PDU; the EH fieldindicates whether an extended header group is present following the GMH;and the length field indicates a length in bytes of the MAC PDUincluding the GMH and an extended header if present.
 7. The methodaccording to claim 1, wherein the SN field is used for an HARQ(hybrid-automatic retransmission request) scheme.
 8. A station forcommunicating in a wireless access system using a medium access controlprotocol data unit (MAC PDU), the station comprising: a transmitter; areceiver; and a processor configured to generate the MAC PDU, whereinthe MAC PDU comprises a MAC header indicated by a MAC header typeparameter determined during a dynamic service flow creation procedure,wherein the MAC header type parameter indicates one of a generic MACheader (GMH) and a short-packet MAC header (SPMH), wherein the SPMHconsists of the flow identifier (FID) field identifying the connectionused for the transmission of the MAC PDU, an extended header grouppresence indicator (EH) field indicating whether an extended headergroup is present following the SPMH, a length field indicating a lengthin bytes of the MAC PDU including the SPMH and an extended header ifpresent, and a sequence number (SN) field indicating a payload sequencenumber of the MAC PDU, wherein the SN field increments by one for eachMAC PDU, wherein a size of the FID field is 4 bits, a size of the EHfield is 1 bit, a size of the length field is 7 bits, and a size of theSN field is 4 bits, and wherein a total size of the SPMH is 2 bytes. 9.The station according to claim 8, wherein the processor comprises aconvergence sublayer, a service data unit (SDU) fragmentation or packingfunction unit, and a MAC PDU formation module which are used forgenerating the MAC PDU.
 10. The station according to claim 8, whereinthe dynamic service flow creation procedure is performed by exchanging adynamic service addition request (AAI_DSA-REQ) message and a dynamicservice addition response (AAI_DSA-RSP) message.
 11. The stationaccording to claim 10, wherein the station communicates with anotherstation using the MAC PDU comprising the MAC header indicated by the MACheader type parameter, wherein the MAC PDU is constructed by the MAC PDUgenerating unit, and wherein the MAC header type parameter has 1 bit toindicate the type of the MAC header.
 12. The station according to theclaim 10, wherein the AAI_DSA-REQ message comprises service flowparameters specifying traffic characteristics and schedulingrequirements of the service flow and convergence sublayer parametersencodings specifying convergence sublayer specific parameters, andwherein the service flow parameters comprise a link indicator indicatingwhether parameters for the MAC PDU transmission is uplink or a downlinkand the MAC header type parameter.
 13. The station according to theclaim 10, wherein the AAI_DSA-RSP message comprises service flowparameters specifying traffic characteristics and schedulingrequirements of the service flow and convergence sublayer parametersencodings specifying convergence sublayer specific parameters, andwherein the service flow parameters comprises a link indicatorindicating whether parameters for the MAC PDU transmission is uplink ora downlink and the MAC header type parameter.
 14. The station accordingto claim 10, wherein the small data packet is a voice over internetprotocol (VoIP) data packet which has a predetermined fixed size with apredetermined periodicity.
 15. The station according to the claim 14,wherein the GMH consists of the flow identifier (FID) field, an extendedheader group presence indicator (EH) field, a length field and asequence number (SN) field.
 16. The station according to claim 15,wherein the FID field identifies the connection used for thetransmission of the MAC PDU; the EH field indicates whether an extendedheader group is present following the GMH; and the length fieldindicates a length in bytes of the MAC PDU including the GMH and anextended header if present.
 17. The station according to claim 16,wherein the SN field is used for an HARQ (hybrid-automaticretransmission request) scheme.
 18. The method according to claim 1,wherein the second MAC header type parameter has 1 bit to indicate thetype of the MAC header.